Question

我使用3个标签构建类似WhatsApp的应用，每个标签都有Fragment。在我的第一个Fragment中，我有RecyclerView。

赢取一套SectionsPagerAdapter以开始使用RecyclerView Fragment的宽度像这样：

inner class SectionsPagerAdapter(fm: FragmentManager) : FragmentPagerAdapter(fm) {

        override fun getItem(position: Int): Fragment {
            // getItem is called to instantiate the fragment for the given page.
            // Return a PlaceholderFragment (defined as a static inner class below).
            //return PlaceholderFragment.newInstance(position + 1)
            when(position){
                0 ->  return Fragmenttask.newInstance()
                1 ->  return FragmentChat.newInstance()
                2 ->  return FragmentMaps.newInstance()
                else  -> {
                    return null!!
                }
            }
        }

        override fun getCount(): Int {
            // Show 3 total pages.
            return 3
        }
    }

它给了我这个错误：

E / AndroidRuntime：致命异常：主要过程：com.deraah.mohamed.deraahpro，PID：21993 java.lang.IllegalStateException：指定的子节点已经有了家长。您必须首先在孩子的父母上调用removeView（）。在android.view.ViewGroup.addViewInner（ViewGroup.java:4937）在android.view.ViewGroup.addView（ViewGroup.java:4768）在android.support.v4.view.ViewPager.addView（ViewPager.java:1477）在android.view.ViewGroup.addView（ViewGroup.java:4708）在android.view.ViewGroup.addView（ViewGroup.java:4681）在 android.support.v4.app.FragmentManagerImpl.moveToState（FragmentManager.java:1425）在 android.support.v4.app.FragmentManagerImpl.moveFragmentToExpectedState（FragmentManager.java:1740）在 android.support.v4.app.BackStackRecord.executeOps（BackStackRecord.java:794）在 android.support.v4.app.FragmentManagerImpl.executeOps（FragmentManager.java:2580）在 android.support.v4.app.FragmentManagerImpl.executeOpsTogether（FragmentManager.java:2367）在 android.support.v4.app.FragmentManagerImpl.removeRedundantOperationsAndExecute（FragmentManager.java:2322）在 android.support.v4.app.FragmentManagerImpl.execSingleAction（FragmentManager.java:2199）在 android.support.v4.app.BackStackRecord.commitNowAllowingStateLoss（BackStackRecord.java:651）在 android.support.v4.app.FragmentPagerAdapter.finishUpdate（FragmentPagerAdapter.java:145）在android.support.v4.view.ViewPager.populate（ViewPager.java:1236）在 android.support.v4.view.ViewPager.setCurrentItemInternal（ViewPager.java:662）在 android.support.v4.view.ViewPager.setCurrentItemInternal（ViewPager.java:624）在 android.support.v4.view.ViewPager.setCurrentItem（ViewPager.java:605）在 android.support.design.widget.TabLayout $ ViewPagerOnTabSelectedListener.onTabSelected（TabLayout.java:2170）在 android.support.design.widget.TabLayout.dispatchTabSelected（TabLayout.java:1165）在 android.support.design.widget.TabLayout.selectTab（TabLayout.java:1158）在 android.support.design.widget.TabLayout.selectTab（TabLayout.java:1128）在 android.support.design.widget.TabLayout $ Tab.select（TabLayout.java:1427）在 android.support.design.widget.TabLayout $ TabView.performClick（TabLayout.java:1537）在android.view.View $ PerformClick.run（View.java:24770）在android.os.Handler.handleCallback（Handler.java:790）在android.os.Handler.dispatchMessage（Handler.java:99）在android.os.Looper.loop（Looper.java:164）在android.app.ActivityThread.main（ActivityThread.java:6494） at java.lang.reflect.Method.invoke（Native Method）在 com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:438）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:807）

更新

我的片段：

FragmentChat：

/**
 * A simple [Fragment] subclass.
 * Activities that contain this fragment must implement the
 * [FragmentChat.OnFragmentInteractionListener] interface
 * to handle interaction events.
 * Use the [FragmentChat.newInstance] factory method to
 * create an instance of this fragment.
 */
class FragmentChat : Fragment() {

    private var mListener: OnFragmentInteractionListener? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        // Inflate the layout for this fragment
        return inflater!!.inflate(R.layout.fragment_fragment_chat, container, false)
    }

    // TODO: Rename method, update argument and hook method into UI event
    fun onButtonPressed(uri: Uri) {
        if (mListener != null) {
            mListener!!.onFragmentInteraction(uri)
        }
    }

    override fun onAttach(context: Context?) {
        super.onAttach(context)
    }

    override fun onDetach() {
        super.onDetach()
        mListener = null
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     *
     *
     * See the Android Training lesson [Communicating with Other Fragments](http://developer.android.com/training/basics/fragments/communicating.html) for more information.
     */
    interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        fun onFragmentInteraction(uri: Uri)
    }

    companion object {

        // TODO: Rename and change types and number of parameters
        fun newInstance(): FragmentChat {
            val fragment = FragmentChat()
            val args = Bundle()
            fragment.arguments = args
            return fragment
        }
    }
}// Required empty public constructor

FragmentMaps：

/**
 * A simple [Fragment] subclass.
 * Activities that contain this fragment must implement the
 * [FragmentMaps.OnFragmentInteractionListener] interface
 * to handle interaction events.
 * Use the [FragmentMaps.newInstance] factory method to
 * create an instance of this fragment.
 */
class FragmentMaps : Fragment() {

    private var mListener: OnFragmentInteractionListener? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        // Inflate the layout for this fragment
        return inflater!!.inflate(R.layout.fragment_fragment_maps, container, false)
    }

    // TODO: Rename method, update argument and hook method into UI event
    fun onButtonPressed(uri: Uri) {
        if (mListener != null) {
            mListener!!.onFragmentInteraction(uri)
        }
    }

    override fun onDetach() {
        super.onDetach()
        mListener = null
    }


    interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        fun onFragmentInteraction(uri: Uri)
    }

    companion object {
        // TODO: Rename and change types and number of parameters
        fun newInstance(): FragmentMaps {
            val fragment = FragmentMaps()
            val args = Bundle()
            fragment.arguments = args
            return fragment
        }
    }
}// Required empty public constructor

Fragmenttask：

class Fragmenttask : Fragment() {

    private var mListener: OnFragmentInteractionListener? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
    }

    override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        val CustumViewtask = inflater!!.inflate(R.layout.fragment_fragmenttask, container, false)
        val taskMainRV = CustumViewtask.findViewById(R.id.recyclerView_main) as RecyclerView
        //taskMainRV.setBackgroundColor(Color.BLUE)

        taskMainRV.layoutManager = LinearLayoutManager(context)
        //recyclerView_main.adapter = MainAdapter()

        fetchJson(taskMainRV)

        return taskMainRV
    }

    fun fetchJson(RSV: RecyclerView) {

        //SharedPreferences
        val MY_APP_INFO: String = "UserInfo"
        val prefs = activity.getSharedPreferences(MY_APP_INFO, AppCompatActivity.MODE_PRIVATE)
        val LoggedUserId = prefs.getString("UserId", null)
        println("your code is : $LoggedUserId")

        println("Attempting to Fetch JSON")

        val url = "http://Restful.com/get_tasks.php"

        val client = OkHttpClient()

        val formBody = FormBody.Builder().add("UserId", LoggedUserId).build()

        val request = Request.Builder().url(url)
                .post(formBody)
                .build()

        client.newCall(request).enqueue(object: Callback {
            override fun onResponse(call: Call?, response: Response?) {
                val body = response?.body()?.string()
                println("mohamed : $body")

                val gson = GsonBuilder().create()

                val tasksfeed = gson.fromJson(body, M_tasksFeed::class.java)

                activity.runOnUiThread {
                    RSV.adapter = MainAdaptertasks(tasksfeed)
                }

            }

            override fun onFailure(call: Call?, e: IOException?) {
                println("Failed to execute request")
            }
        })
    }

    // TODO: Rename method, update argument and hook method into UI event
    fun onButtonPressed(uri: Uri) {
        if (mListener != null) {
            mListener!!.onFragmentInteraction(uri)
        }
    }

    override fun onDetach() {
        super.onDetach()
        mListener = null
    }

    /**
     * This interface must be implemented by activities that contain this
     * fragment to allow an interaction in this fragment to be communicated
     * to the activity and potentially other fragments contained in that
     * activity.
     *
     *
     * See the Android Training lesson [Communicating with Other Fragments](http://developer.android.com/training/basics/fragments/communicating.html) for more information.
     */
    interface OnFragmentInteractionListener {
        // TODO: Update argument type and name
        fun onFragmentInteraction(uri: Uri)
    }

    companion object {
        fun newInstance(): Fragmenttask {
            val fragment = Fragmenttask()
            val args = Bundle()
            fragment.arguments = args
            return fragment
        }
    }
}// Required empty public constructor

Answer 1

您错误view检入 Fragmenttask Fragment

使用此

 return CustumViewtask

而不是

return taskMainRV

像这样更改你的代码

override fun onCreateView(inflater: LayoutInflater?, container: ViewGroup?,
                              savedInstanceState: Bundle?): View? {
        val CustumViewtask = inflater!!.inflate(R.layout.fragment_fragmenttask, container, false)
        val taskMainRV = CustumViewtask.findViewById(R.id.recyclerView_main) as RecyclerView
        //taskMainRV.setBackgroundColor(Color.BLUE)

        taskMainRV.layoutManager = LinearLayoutManager(context)
        //recyclerView_main.adapter = MainAdapter()

        fetchJson(taskMainRV)

        return CustumViewtask
    }

Answer 2

来自

的问题

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<button type="button" class="btn btn-success btn-sm view-profile" data-citizens='{ "id" : 1}'> Profile</button>

试试这种方式

       else  -> {
                return null!!
            }

<强> override fun getItem(position: Int): android.support.v4.app.Fragment { // getItem is called to instantiate the fragment for the given page. // Return a PlaceholderFragment (defined as a static inner class below). //return PlaceholderFragment.newInstance(position + 1) var fragment: android.support.v4.app.Fragment? = null when (position) { 0 -> fragment = Fragmenttask.newInstance() 1 -> fragment = FragmentChat.newInstance() 2 -> fragment = FragmentMaps.newInstance() } return fragment!! } override fun getCount(): Int { return 3 //no of cases/fragments } }

您必须致电removeView()。

每个片段部分

FYI

Answer 3

您是否确定在展开片段视图时已将attachRootView设置为false？

inflater.inflate(R.layout.fragment, container, false)

将Fragment与制表符一起使用..指定的子节点已有父节点

3 个答案: